Train brake equipment



June 22, J, Vyl LOGAN, JR

TRAIN BRAKE EQUIPMENT Filed Sept. 18, 1935 INVENTOR JOHN w. L oQANpR.

ATTORN Y W5 MS N w n n Q Patented June 22, 1937 UNITED STATES PATENT OFFIQE TRAIN BRAKE EQUIPMENT Application September 18, 1935, Serial No. 41,012

24 Claims.

This invention relates to a brake equipment for use on multiple unit cars and railway trains, and more particularly to such equipment adapted for use on high speed trains.

In certain types of high speed train braking equipments a straight air controlled portion is provided for effecting service application of the brakes, and an automatic controlled portion is also provided for effecting service applications in case of failure of the straight air controlled portion, and for effecting emergency applications. An automatic application of the brakes will result in case of a broken train, and it may also be effected from any car of thetrain.

A uniform braking pressure is assured in the several brake cylinders in the case of the straight air controlled application since the several brake cylinders are all supplied with fluid under pressure in accordance with the fluid pressure developed in the common straight air pipe. In the case of an automatic brake application, however, upon a reduction in brake pipe pressure Huid under pressure is supplied to each brake cylinder from the associated auxiliary reservoir and there is a possibility that differences within the several brake cylinders may result, caused by leakage from the brake cylinders, Variations in brake cylinder piston travel, and the like, and which will produce different braking forces at different points on the train.

It has been proposed to employ an .automatic brake system to initially apply the brakes and to thereafter maintain the brakes applied by a straight air system in which the brake cylinder pressure corresponds at all times to the straight air pipe pressure. Such a combined brake equipment however requires the use of two train line pipes, one pipe being the straight air pipe of the straight air system and the other being the brake pipe (or emergency pipe) of the automatic system.

In accordance with my invention I propose to provide a single pipe brake equipment of the automatic type in which the brake cylinder pressures are regulated under self maintaining and equalization control as now customary only with straight air equipment. I propose to provide means for varying the brake cylinder pressure inversely as the pressure in the brake pipe varies. My proposed system differs from the conventional automatic brake system in that brake cylinder pressure continues to increase upon a continuing lowering of the brake pipe pressure, even below 55 the pressure at which brake pipe pressure normally equalizes with the customary auxiliary reservoir in the conventional automatic system, the brake cylinder pressure reaching its maximum value as the brake pipe pressure approaches Zero.

It is an object of my invention to provide a fluid pressure brake equipment that is quick acting both when applying and when releasing the brakes.

It is another object of my invention to provide means for effecting an automatic application of the brakes and for maintaining equalization of brake cylinder pressure in the several brake cylinders of the braking unit.

It is a further object of my invention to provide means for regulating the brake cylinder pressure inversely with variations in the brake pipe pressure below a chosen value regardless of the degree of reduction in brake pipe pressure.

It is a further object of my invention to provide means of the above in-dicated character in which the brake cylinder pressure continues to increase while the brake pipe pressure continues to decrease to substantially Zero pressure.

It is a further object of my invention to provide, in a system of the above indicated character, a retardation controlled equipment for controlling the brake system to limit the rate of retardation of the vehicle in accordance with a desired value.

Other objects and advantages of my invention will be apparent from the following description of one embodiment thereof taken in connection with the accompanying drawing, in which Fig. l is a diagrammatic view illustrating apparatus comprising one preferred embodiment of my invention, and

Fig. 2 is a detail of a portion of the means for operating a relay valve device.

Referring to Fig. l of the drawing a braking equipment may comprise a plurality of braking units, one only being illustrated. Each local braking unit of the train may comprise brake cylinders I and 2 that are supplied with iiuid under pressure through the brake cylinder pipe 3 in accordance with the operation of a relay valve device 4 that controls the supply of fluid under pressure from the local reservoirs 5 and 5 of the unit to the brake cylinders in accordance with variations in the sum of the pressures within the diaphragm chambers 'l and 8 from a predetermined value. The pressure within the diaphragm chamber 'I corresponds to that within the brake pipe 9, that extends the length of the train and is connected to all braking units of the train and the ultimate pressure in the chamber 8 corresponds to brake cylinder pressure, the sum of these two pressures balancing the force of a spring I23 when the controlled valves are in lap position. Fluid under pressure flows to the brake pipe 9 from the main reservoir II as supplied by a feed valve device I2 through a supply magnet valve device I3 and a brake valve device I4. The pressure within the diaphragm chamber 8 is controlled in part by the brake pipe pressure in response to the operation of the brake valve device I4, and in part by the operation of a discharge magnet valve device I5 and a supply magnet valve device I 6 that are controlled in accordance with the operation of a. retardation controller Il. The supply magnet valve device i3 and the discharge cut-ofi magnet valve device I8 are controlled either in accordance with the operation of the brake valve device I4 or in accordance with the operation of the emergency relay I9, that is controlled in accordance with the operation of the deadman switch 2| or the conductors switch 22. The emergency relay i3, in addition to controlling the supply magnet valve device I3 and the discharge cut-oil` magnet valve device I8, also controls the discharge magnet valve device I5 and the supply magnet valve device i6, associated with each local braking unit of the train to effect an emergency operation of the brak-es independently of the operation of the brake valve device Ibi.

The brake valve device lll comprises a casing 23 dening a pressure chamber 24 that is in constant open communication with the brake pipe 9. A supply valve chamber 25 is also provided in the casing to which fluid under pressure is supplied from the main reservoir II at a reduced pressure, as supp-lied by the feed valve device l2 of the usual type, through the pipe 26 as controlled by the supply magnet valve device i3. A supply valve 2l is contained within the supply valve chamber 25 and is slidably disposed within a bore 28 in the casing to engage a seat 29 carried by a portion of the casing forming one wall of the chamber 2:3. The supply valve 2l is subject to the pressure of a spring 3l, one end of which engages the valve and the other end of which engages the outer wall of the casing. A stem or rod 32 is provided, one end of which is attached to the supply valve 2'I and the other end of which extends through an opening 33 in the outer wall of the casing adjacent a Contact member 34 that is adapted to engage a switch contact member 35, the contact members 314 and 35 comprising a switch for closing a circuit upon the movement oi the supply valve 21 toward the left. The contact members 34 and 35 are mounted in a base of insulating material 3E and a stop 3l is provided for preventing the contact member 35 from moving toward the right beyond a predetermined point, to insure the separation of the contact members34 and 35 upon movement of the stem 32 toward the right.

The casing 23 is also provided with a cylinder 38 which is open at one end to the pressure chamber 2li, the other end of the cylinder being closed by an adjusting member 39 screw-threadedly attached within a bore in the casing section. Operatively mounted in the cylinder 38, adjacent its open end, is a movable abutment in the form of a piston M having a stern 42 which is slidably guided by the adjustable member 39 within the bore 43. At one end of the piston 4I is a chamber a4 which is normally open to the atmosphere through the passage and pipe E5 and the discharge cut-oir magnet valve device I8. A regulating spring 45 is contained in the chamber 44 and is interposed between and engages the inner face of the piston 4I and the inner face of the adjusting member 39.

A discharge valve chamber l? is provided within the piston il! and is in open communication with the pressure chamber 2d through a passage 48. A discharge valve 9 is contained within the valve chamber 4l and is adapted to scat on a valve seat 5i formed on the piston and which is operated to control communication between the valve chamber il and the chamber d through connecting passages 52 in the connecting stem ft2. The discharge Valve is provided with a stem 53, the small end of which slides within a bore in the stem 42 of the piston 4I and is operable to hold a spring pressed switch blade 5d out of circuit closing position when the discharge valve i9 is in engagement with its valve seat 5i. The larger end of the discharge valve stem 53 is provided with a collar 55 which slidably engages the piston within a central bore 56 and is subject to the pressure oi a discharge valve spring 5l interposed between the collar 55 and the annular flange 53 on the piston GI. Outward movement of the discharge valve relative to the piston 4I is limited by the collar 55 which engages a stop plate 59 that is secured to the piston fil.

Mechanism is provided for controlling the operation of the supply valve 21 and the discharge valve 49, comprising a lever (il that is pivotally mounted on a pin 62 carried by a plunger' 63 that is slidably guided within the bore 6d within the wall of the casing.

The upper end ci the lever El is provided with a rounded portion 65 that is adapted to operatively engage the outer end of the discharge valve stern 53. The lower end or" the lever Si is provided with a recess 66 into which one end of a rod El is tted, the opposite end of the rod operatively engaging the supply valve 2i within a recess formed in its face.

For the purpose of operatingthe plunger 63 toward the left there is provided an operating shaft 5c provided with a cam Gil and operated by a lever 10.

It will be appreciated that the force of the discharge valve spring 57 is less than that of the supply valve spring 3l, which is less than that of the regulating spring 4B, so that upon movement of the plunger 63 toward the left the discharge valve 49 will engage the valve seat 5I before the supply valve 27 is moved away from its valve seat 29. When the system is charged and the shaft 5D, the cam 6c, and lever 'I0 are in their release positions, as shown in Fig. 1 of the drawing, the discharge valve 49 is forced to its seat 5I thus closing communication from the pressure chamber 24 to the atmosphere, and the supply valve 21 is forced t'o its seat 29 by the supply valve spring 3|.

The brake valve device I4 is also provided with an emergency valve 88 that is adapted to engage the rib seat 89 and is provided with a stem 9! extending into the pressure chamber 211. The valve 88 is normally urged to its seat by a spring 92, and is forced from its seat against the force of the spring 92 upon engagement of the cam 60 With the stem BI as the lever 1d 4is moved to emergency position, in which position iiuid under pressure is released from the pressure chamber 24 past the emergency valve 8S through the exhaust port 93.

The supply magnet valve device I3 comprises a casing enclosing a chamber 68 that is in open communication with the pipev 2G, and with a valve chamber 69 that is in open communication through a pipe ll with the supply valve chamber 25. A valve 'l2 is provided within the valve chamber 39 that is adapted to engage the seat 'i3 to control communication between the valve chamber 69 and the chamber 8 upon energization of the magnet 14 of the magnet valve device. A spring l5 is provided within the chamber 68 for urging the valve 12 from its seat.

An exhaust cut-off valve device I8 comprises a casing 8| enclosing a chamber 82, that is in constant communication with the chamber 44 of the brake valve device through pipe 45, and a valve chamber 83, that is in constant communication with the atmosphere through the exhaust port 84 and which contains a valve 85 that is connected by means of a stem with the operating magnet 86. A spring 81 is provided within the chamber 82 for forcing the valve 85 from its seat.

The relay valve device 4 comprises diaphragm operated devices 94 and S5 containingfrespectively the diaphragm chambers 'l and S, and a casing 96 containing a piston chamber 91. The relay valve device is operative to control the supply of iiuid under pressure from the local reservoirs 5 and 6 of a braking unit to the brake cylinders and 2 of that unit in accordance with the pressure within the piston chamber Sl as supplied through the supply pipe and passage 98, the diaphragm operated valve device 95 and passage 39 to the piston chamber Sil. The piston chamber 91 contains a piston Si! that is adapted through the medium of a stem |60 to operate a slide valve ||l| that is operatively connected to the stem and contained in a slide valve chamber |82 that is constantly connected to the brake cylinders and 2 through brake passage and pipe 3. Also contained in the casing is a fluid pressure supply valve |23 which is subject to the pressure of the spring |54 and which is provided with a stern |95 that is adapted to operatively engage the end or" the piston stem |00.

The relay valve device 4 is shown with the relay piston 9E] and the slide valve Ii in their extreme left or brake releasing positions. With the slide valve IGI in this position, the valve chamber |32 and consequently the brake cylinders and 2 are connected to the atmosphere through an exhaust chamber |35 and an exhaust passage and pipe |01. With the piston in release position the stem |89 will be out of engagement with the end ci the supply valve stem |05 so that the presu sure of the spring |34 will maintain the supply valve |93 seated against its seat rib |68, thereby maintaining communication closed from a supply valve chamber |39 that is constantly connected to the local reservoirs 5 and 8 through passage and pipe 98, to the slide valve chamber |32.

The diaphragm operated devices 94 and 95 contain, respectively, diaphragm chambers l and 8 containing equal area diaphragms and ||2 which engage followers ||3 and ||4 connected, respectively, to the stems ||5 and ||6 that are positioned to operate at a common radius from the shaft I9 through upwardly extending levers Hl' and ||8 to rotate the shaft ||9 in a clockwise direction. In order to provide means for accurately adjusting the relative positions of the leversA lil and lla, one of them, as Ill, may be loosely mounted on the shaft ||9 and positioned with respect thereto by a set screw H0. The shaft H9 is mounted upon a bracket |2| connected to the casing 93 and the lever ||8 is provided with a downwardly extending arm |22 that operatively engages one end of a spring |23, the other end of which is positioned in a recess in the casing 96, for biasing the shaft ||9 in a counterclockwise direction against the pressure in the diaphragm chambers 'l and 8.

The spring |23 is so designed and adjusted by the set screw |20 as to just balance a predetermined pressure, say 60 pounds, in either one of the diaphragm chambers 'I and 3 when the other diaphragm chamber is at atmospheric pressure. It will b-e understood therefore that the force of the spring |23 will balance the force of the diaphragm stems lit and ||6 when the sum of the pressures in the two diaphragm chambers 'l and 8 is equal to the predetermined pressure, such as 60 pounds. If, for example, the pressure in the diaphragm chamber 'l is 4G pounds, then the pressure within the diaphragm chamber 8 required to balance the force of the spring |23 will be 20 pounds. The diaphragm chamber l is connected directly to the brake pipe 9 so that the pressure within the chamber l is always brake pipe pressure.

A chamber 24, that is in constant communication with the local reservoirs 5 and t through the passage and pipe 98, is contained within the casing comprising the diaphragm operated device 95. The inlet valve |25 is provided for oontrolling communication between the chamber |24 and the diaphragm chamber 3 and is provided with a valve stem |25 extending through a bore in the partition wall between the two chambers and engages the diaphragm H2. A spring |21 is provided for urging the inlet valve |25 to its seat and when the pressure within the diaphragm chambers l and 8 is insuicient to overcome the force of the spring |23, the spring |23 causes the shaft H9 to rotate in a counterclockwise direction, the inlet valve |25 being thus forced from its seat against the bias of the spring I2? by the diaphragm ||2 and the follower ||l.

The diaphragm chamber 8 is in communication with an exhaust valve chamber |28 through a restricted passage |40 and the passage 99. exhaust valve chamber |28 contains an exhaust valve |29 having a stem |3| that is adapted to be engaged by a set screw |39 carried by the lower portion of the downwardly extending lever |22 and is normally biased to its seat by a spring |33 within the valve chamber |28. The exhaust valve |29 controls communication from the diaphragm chamber 8 and from the exhaust valve chamber |28 to the atmosphere through the exhaust passage 32 in accordance with the move- .f

ment of the shaft H9 and the downwardly extended lever |22.

Each local discharge magnet valve device l5 comprises a casing containing a discharge valve chamber |34 that is in constant communication with the brake pipe 9 and an exhaust chamber |35 that is in constant communication with the atmosphere through an exhaust port |33. The valve chamber |34 contains a discharge valve |31 that is connected by means of a stem to the operating magnet |38, and a spring |39 is provided within the valve chamber |34 for urging the valve |31 towards its seat.

Each local supply magnet valve device I6 is provided with a casing containing a supply valve chamber |4| that is Connected by means of a pipe |42, check valve |43 and pipe |44 to the local reservoir 5, and with a chamber |45 that is in constant communication with the brake pipe 9. A supply valve |43 is provided for con- The i Afil trolling communication between the valve chamber MI and the chamber |45, and is provided with an upwardiy extending stem that is operatively connected to the magnet |41. A spring |43 is provided within the valve chamber |l|| for urging the valve |45 toward its seat. The check valve |43 prevents the ilovv of fluid under pressure from the brake pipe 9 to charge the reservoirs 5 and 6 through the magnet valve device 6.

Fluid under pressure is supplied to the local reservoirs 5 and 9 from the main reservoir I| through the brake pipe 9, a cut-off valve device |5|, and a one-way check valve |52. A one-way check valve |53 is provided between the local reservoirs 5 and 5 to prevent back-110W of fluid under pressure from the reservoir 5 into the reservoir 5 upon a reduction in pressure in the reservoir 5, thus maintaining the fluid in the reser-` voir 5 for supplying the brake cylinders.

The cutnoff valve device |5| comprises a casing enclosing a piston chamber |55 containing a piston |55 that is operatively connected by a stem |55 to a, valve |51 for controlling communication between the piston chamber |55, that is ln constant communication with the brake pipe 9, and the chamber |59. The space |5| above the piston |55 is connected to the atmosphere through a port |62 and is provided with a spring |53 for urging the valve |51 to its seat. The spring |63 is so adjusted that the valve |51 is moved from its seat only when the pressure within the piston chamber |54 is as great as, or greater than, the combined pressures in the dia phragms 1 and 8 required to balance the pressure of the spring |23, say, for example, pounds per square inch. When the pressure Within the brake pipe 9 exceeds this predetermined value the piston |55 is forced upwardly against the pressure of the spring |63, thus lifting the valve |51 from its rib seat |95 and permitting the flow of fluid under pressure from the brake pipe 9 through chambers |54 and |58, past the one-way check valve |52 into the local reservoir 5, and past the one-way check valve |53 into the local reservoir 5. The flow of huid under pressure from the local reservoirs 5 and 5 to the brake pipe 9, upon the lowering of the brake pipe pressure, is prevented by the check valves |53, |54 and the cut-off valve |51.

The retardation controller |1 comprises an insulating base |1| in which are mounted spring' contacts |12 and |13 that are separated by insu* lating material |14 and are adapted to be moved upon movement of an inertia device, such as the pendulum |15 that is pivotally supported on the pin |15 and is mounted to freely move toward the left in accordance with the rate of retardation of the vehicle. A spring contact finger |11 is normally in engagement with the contact member |13 and is provided with a stop |18 for limiting its motion toward the left upon movement of the contact member |13 in that direction. The contact member |12 is adapted to engage the contact ngxers |19 upon a predetermined movement toward the left, and, upon a further predetermined movement, to engage the contact nger |8|. Stop members |32 and |83 are respectively provided for the contact iingers |19 and |8| to limit their movement toward the right as the contact member |12 moves in that direction out of engagement with the iingers |19 and |B|.

The deadman switch 2| comprises a movable contact member |85 that is adapted to engage the contact member |35 and is urged out of engagement therefrom by a spring |85` The deadman switch 2| is maintained in circuit closing position so long as manual pressure is exerted upon the movable Contact member |84 to forceit into engagement with the contact member |85 against the force of the spring |85.

The conductors switch 22 comprises a movable contact member |81 that is adapted to engage a fixed contact member |38 and is normally maintained in engagement therewith by a spring l 89 and is adapted to be moved from engagement therewith by a manually operable means such as the handle |92.

IThe emergency relay i9 comprises an operating winding |9| and two movable contact members |92 and |95 that are illustrated in their upper positions, which are the positions effected upon the energization of the winding |9I, which is energized through a circuit extending from the positive terminal of the battery 209, through conductor |55, the Winding |9| yof the relay I9, conductor |95, the deadman switch 2|, conduc-V tor |91, conductors switch 22, conductor |98, a conductor |99 representing the train conductor ior each of the several cars of the train, through a jumper 29| at the rear of the train, and by return conductors 252 and 293 to the negative terminal of the battery 259.

The operation of the system will now be described. When the train is in operation, the system is charged, and the brake valve handle l5 is in its illustrated position, the brakes will be released and the several parts of the equipment will be in their illustrated positions. The windings of the several magnet valve devices |3, i5, |t and I3 will be deenergized.

Ii the handle 15 is positioned in its release position prior to charging of the equipment, the pressure within the pressure chamber 25 will be insufficient to overcome the force of the regulating spring t5 acting on one side of the movable abutment or piston 5|, and this piston will be forced toward the right by the regulating spring l5 with sufiicient force that the discharge valve stem 53 which engages the rounded end 55 of the lever 5| will pivot this lever about the pin 62 causing the rod 61 to force the supply valve 21 toward the left from its seat 29 against the bias of the supply valve spring 3|, and effecting communication between the main reservoir and the pressure chamber 24. to charge the system will thus flow from the main reservoir at a reduced pressure as supplied by the feed valve device I2, through pipe 25, the supply magnet valve device I3, pipe 1|,

the supply valve chamber 25 to the pressure chamber 25| and to the brake pipe 9.

Upon the flow of fluid under pressure from the main reservoir to the supply chamber 24 and to the brake pipe 9, pressure is exerted on the chamber sid-e of the piston 5| in opposition to the pressure exerted by the regulating spring 55. This pressure continues to build up until it becomes sufcient to force the piston 4| toward the left, relieving the pressure on the rounded end 55 of the lever 6| and permitting the supply valve spring 3| to force the supply valve 21 to its seat 29, and rod 51 toward the right, pivoting the lever 6| about the pivot pin 52. The amount of pressure on the chamber side of the piston 4| necessary to effect a sufficient movement of the piston il to cause the supply valve 21 to seat is dependent upon the stiffness of the regulating spring 45, which is adjusted by movement of the adjustable member'39 to such value as to effect the .full desired brake pipe pressure.

Fluid under pressure Since the force of the regulating spring 45 is exerted on the lever 6| through the discharge valve stem 53, and since the force exerted by the discharge valve spring 51 is less than the force exerted by the supply valve spring 3|, the valve 49 is held against its seat 5I.

At the time the supply valve 21 is unseated to eiect charging or the brake pipe 9 the magnet of the magnet valve device IB will be energized through a circuit extending from the positive terminal of the battery 200 through conductor |05, conductor 204, the Contact members 34 and 35 that are controlled by the supply valve 21, conductor 205, the contact member |92 of the emergency relay IS, conductor 206 and the winding of the magnet |41 of the magnet valve device I6, and conductor 203 to the negative terminal of the battery 200.

When the supply valve 21 is` moved to its seat and the stem 53 is moved toward the right, away from the switch spring contact 34 this contact moves out of engagement with the switch contact member 35 to interrupt the above traced circuit through the winding of the magnet |41 of the local supply magnet valve device I6, thus deenergizing this magnet and permitting the valve |45 to be forced to its seat by the spring |48 to prevent the flow of fluid under pressure from the local reservoir 5 through the supply magnet valve device IB to the brake pipe 9 upon the reduction in brake pipe pressure. This operation ci the valve |46 has no significance during the initial charging of the system since the supu ply reservoir 5 has not been charged and the check valve |43 prevents it from being charged from the brake pipe 9 through the magnet valve device I5.

When the pressure in the brake pipe 9 has increased sufficiently to effect the full release of the brakes, and has reached the predetermined value at which the pressure on the under side of the piston |55 overbalances the force of the spring |53, the valve |56 is unseated to effect the charging of the reservoirs 5 and 6 from the brake pipe 9 through the cut-off valve device I5I. The check valve |52 prevents the brake pipe 9 from being recharged by the flow of fluid under pressure from the reservoir 5 through the cutoff valve device I5| upon a reduction in brake pipe pressure, thus maintaining the pressure within the reservoir 5 until the magnet valve device Iii is operated to effect the recharge of the brake pipe through the magnet valve device IG. The check valve device |53 prevents the flow of iiuid under pressure from the local auxiliary reservoir 5 to the supply reservoir 5 upon a reduction in pressure in the reservoir 5 thus preventing the loss of pressure from the reservoir 6 upon the recharge of the brake pipe 9 from the reservoir 5 to maintain the supply of fiuid under pressure in the reservoir 6 available at all times for supply to the brake cylinders l and 2;

From the brake pipe fluid under pressure flows to charge the diaphragm chamber 1 of the diaphragm operated device 94 and also to charge the valve chamber E34 of the discharge magnet valve device i and the chamber |45 of the supply magnet valve device 0. Fluid under pressure at brake pipe pressure also ows to the piston chamber l5fl of the cut-01T Valve device ki 5| and when the pressure within the brake pipe has risen to the predetermined amount, say 60 poundsper square inch, at which the force against the piston |55 becomes greater than the force of the spring |53, the piston |55 and the valve |51 are moved upwardly to open communication from the brake pipe 9 through chamber |54, check valve 'device |52 to the local reservoir 5 and through check valve device 53 to the local reservoir 6. Fluid under pressure also ilows from the pipe |44 past check Valve device |43 to the valve chamber |4| of the local supply magnet valve device I6. Since the cutoli valve device |5| is so adjusted that charging of the local reservoirs 5 and 5 from the brake pipe 9 is permitted only when the pressure within the brake pipe has reached the predetermined amount, say 60 pounds, at which the brake pipe pressure within the diaphragm chamber 1 of the diaphragm operated device 94 is sufficient to rotate the shaft I i9 in a clockwise direction against the force of the spring |23, the charging of the local reservoirs 5 and 6 takes place only when the exhaust valve |29 is unseated and when the pressure in the piston chamber 91 of the relay valve device 4 and in the brake cylinders and 2 is at atmospheric pressure.

If the operator new wishes to make a service application of the brakes the lever of the brake Valve device I4 is moved from its release position, thus moving the shaft 50 and cam 50 of the brake valve device. I4 in a counterclockwise direction an amount dependent upon the desired degree of application of the brakes. Upon suc-h movement of the cam 60, the pressure against the plunger 53 is released and the discharge valve 53 is forced by the discharge valve spring 61 from its` seat 5|, thus permitting the escape of fluid under pressure from the pressure chamber 24 of the brake valve device I4 and from the brake pipe 9, through passage 40, discharge valve chamber 41, passages 52, chamber 44, and through passage and pipe 45 to the chamber 82 of the discharge cut-off magnet valve device I8, past the unseated valve 85 to the atmosphere through the exhaust port 84, thus `decreasing the pressure in the brake pipe 9 and in the diaphragm chamber 1 of the diaphragm operated device 94 constituting a part of the relay valve device 4.

As the discharge valve 49 is moved from its seat the stem 53 is moved toward the right away from the spring contact member 54 which moves into engagement with the contact member 201 to close circuits for energizing the winding of the supply magnet valve device I3 and the windings of the several local discharge magnet valve Idevices I5 that extend from the positive terminal of the battery 200 through conductor |05, conductor 204, the switch contact members 201 to` 54, to the conductor 208, at which point the circuits divide, one circuit extending through the winding of the magnet 14 of the supply magnet valve device I3 and conductor 209 to the negative terminal of the battery 200. The winding of the magnet 14 thus energized causes the valve 12 to be moved 'downwardly against its seat 13 and close communication from the main reservoir to the pressure chamber 25, while uid under pressure is being released to the atmosphere from the pressure chamber 24. The other branch of the divided circuit is completed from the conductor 203 to the contact members |13 and |11 of the retardation controller to the train line conductor |80, through the windings of the magnets |38 of the discharge magnet valve devices I5 toy the train line conductor 203 and to the negative terminal of the battery 200. The winding of the magnet |38, thus energized, forces lil the valve |37 from its seat and effects the release of fluid under pressure from the brake pipe 9 through the exhaust port |35 to also elTect a reduction in brake pipe pressure.

The amount of decrease in iluid pressure in the pressure chamber 21| and in the brake pipe 9 upon movement of the lever 'lil from its release position is dependent upon the amount of movement of the cam 6B, and, consequently, the amount of movement of the piston 4| necessary to again cause the discharge valve 59 to engage its seat 5| upon movement of the piston 4| toward the right. As the pressure in the pressure chamber 2 decreases the adjusting spring M5 forces the piston ill toward the right until the stem of the discharge valve 49 has again engaged the rounded portion S5 of the lever thus forcing the valve it to its seat 5| to close communication from the pressure chamber 24 to the atmosphere through the passages above described.

When the pressure in the brake pipe 9, and in the pressure chamber decreases belovv the value necessary to balance the force of the spring it, the lever |22 and the shaft l I9 are forced by the spring |23 in a counterclockwise direction, thus permitting the exhaust valve |29 to be forced to its seat by the spring 33 and close communication from the diaphragm chamber 8 and from the piston chamber 9| to the atmosphere through the exhaust port |32. At the same time the inlet valve is forced against the pressure oi' the spring |21 through operation of the lever l i8, the stem i i5, the follower ||s and the diaphragm H2, thus permitting the flow of iluid under pressure from the local reservoirs 5 and 6 through pipe and passage 98 to the inlet valve chamber lZ, past the unseated inlet valve |25 to the diaphragm chamber t and to the piston chamber 9| of the relay valve device ll. The flow of fluid under pressure to the chamber 8 and to the piston chamber 9| will continue until the pressure Within the diaphragm chamber 8 has reached such a value that the combined pressures Within the diaphragm chambers i and 8 are sufficient to force the shaft l i9 in a clockwise direction against the force of the spring |23 to permit the inlet valve |25 to seat. The pressure Within the diaphragm chamber 8 and the piston chamber 97| is therefore determined by the amount of the release of the brake pipe pressure below the value required in the diaphragm chamber to balance the force of the spring |23. For example, it the balancing pressure is 60 pounds and the pressure in the brake pipe 9 is reduced to 40 pounds the pressure required in the chamber 8 will be 20 pounds.

Upon the low of fluid under pressure to the piston chamber 9|, the piston 90 and the stem |00 move toward the right, thus moving the slide valve lill to lap the passages 2| and 2 I2 through which the slide valve chamber ||l2 is connected to the atmosphere, and, as the piston Sil continues to move toward the right the end of the stem lil engages the end of the supply valve stem |95 to force the supply valve |03 from its seat against the pressure of the spring |64 and.

permit the ow of fluid under pressure from the local reservoir 6 through the supply pipe and passage 9S, the supply valve chamber |05, past the unseated supply valve |03 to the slide valve chamber m2 and through brake pipe passage and pipe 3 to the brake cylinders l and 2. As the pressure in the slide valve chamber IGZ rises, fluid under pressure ows through the restricted port 2|@- into a chamber 2|5 on the rear ofthe piston 9|! that is sealed from the supply valve chamber |02 by a phantom piston 2|6. When the pressure in the chamber 2|5 becomes equal to the pressure in the piston chamber 97, the force of the supply valve spring |64 exerted through the supply valve stem |65 that is in engagement with the piston stem |06 will force the piston and its stem and the slide valve lill suciently toward the left to permit the seating of the supply valve |63, While maintaining the slide valve lill in lap position, thus maintaining a pressure within the brake cylinders l and 2 corresponding to the pressure Within the piston chamber 91.

If the operator desires a greater degree of application of the brakes the handle 'it is moved further from its release position thus effecting a greater decrease in the pressure within the pressure chamber 24| of the brake valve device |4 and Within the brake pipe 9 which effects a corresponding increase in the pressure Within the diaphragm chamber 8 and the piston chamber 91 of the relay device 4 and a corresponding increase in the pressure Within the brake cylinders and 2 inthe manner already described.

If the operator Wishes to release the brakes the handle 'lll is moved to its release position thus eiecting the supply of fluid under pressure from the main reservoir l l past the unseated supply valve 21 to the pressure chamber 24 and to the brake pipe 9 in the manner above described for charging the system.

The magnet valve devices |S are energized through the switch Contact members 34 and 35 controlled by the supply valve 21 to unseat the valves |55 to also effect the supply of uid under pressure to the brake pipe S from the reservoir E. .Should the flow of fluid under pressure from the reservoir 5 to the brake pipe 9 through the magnet valve device I6 continue sufliciently that the reduction in reservoir pressure and the increase in brakepipe pressure causes these tWo pressures to equalize, the flow of fluid under pressure from the brake pipe through the magnet valve device i6 to the reservoir 5, upon a further increase in brake pipe pressure is prevented by the check valve |43, thus aiding in effecting a more rapid build-up in brake pipe pressure. When the build-up in brake pipe pressure has continued suiiciently to effect the full release of the brakes, or has reached the predetermined value at which the pressure on the under side of the piston |55 of the cut-off valve device |5| over-balances the force of the spring |63 the valve |56 is lifted from its seat to effect the recharging of the reservoir 5 from the brake pipe 9 through the cut-off valve device |5|.

As the pressure in the brake pipe increases during the release of the brakes, the pressure in the diaphragm chamber 'l causes the shaft H9 and the lever |22 to be moved in a clockwise direction against the pressure of the spring |23 thus seating the inlet valve |25 and unseating the exhaust valve |29 to permit the release of fluid under pressure from the diaphragm chamber 8 and from the piston chamber 97 to the atmosphere through the passage ES and the exhaust port |32.

Should the operator Wish to make an emergency application of the brakes the handle l is moved to emergency position in which posi tion the flat side of the cam il@ engagethe emergency valve stem 9| forcing the emergency valve 89 from its seat against the force of the spring SZ, thus permitting fluid under pressure to be released from the brake pipe 9 and the pressure chamber 24 through the exhaust port 93 to effect a rapid decrease in brake pipe pressure. This decrease in pressure is independent of the discharge cut-oir valve device I8.

It will be noted that when the handle 10 of the brake valve device was moved from release position to an application position, the brake valve discharge cut-ofi valve device I8, which had been deenergized and in a position to effe-et communication from the chamber 44 or the brake valve device to the atmosphere remained in that position. 'Ihe supply magnet valve device I3 became energized upon closure of the circuit through the switch contact members 54 and 201, thus causing the valve 12 to close communication from the main reservoir II to the pressure chamber 24 of the brake valve device and to the brake pipe 9. The winding of the local discharge magnet valve devices I5 also became energized upon engagement of the switch contact members 54 and 201, to effect the release of fluid under pressure therethrough and effect a more rapid rate of reduction in brake pipe pressure. The local supply magnet valve devices I5 of the several local braking units which became deenergized upon separation of the switch contact members 34 and 35 upon completion of the charging of the system, remain deenergized thus maintaining the valves |46 in position to close communication from the local reservoirs 5 through the valve devices I5 to the brake pipe 9.

Should the rate of retardation of the vehicle become suicient to cause the inertia pendulum |15 to move forward, or toward the left as viewed in the drawing, sufficiently to cause the switch contact member |13 to separate from the contact member |11 the circuit through the winding of the magnet of the local dis-charge magnet valve device I5 will be interrupted, thus causing the valve |31 to be seated by the spring |39 and prevent further decrease in brake pipe pressure occasioned by the release of fluid under pressure through the magnet valve devices I5. At the same time the switch contact members V2 and |19 are brought into engagement, thus completing a circuit through the winding of the magnet 8,6 of the cut-off magnet valve device I8 causing the valve to be seated and prevent the further iiow of fluid under p-ressure from the pressure chamber 24 to the atmosphere through the exhaust port 84. If the rate of retardation of the vehicle becomes suicient so that the pendulum |15 moves forward suiiiciently to cause engagement of the contact member |12 with the contact member ISI a circuit is also completed for energizing the winding of the local supply magnet valve devices I6, to permit the valves |45 to be forced from their seats and eiTect communication from the local reservoir 5 to the brake pipe 9 to increase brake pipe pressure and thus decrease the degree of application of the brakes. This circuit extends from the positive terminal of the battery 295 through Contact members |12 and |8I or the retardation contro-ller device I1, through conductor 296, the winding of the magnet |41 and co-nductor 253 to the negative terminal of the battery 20B. Upon movement of the switch member |12 from engagement with the switch contact members IBI and |19 the reverse operation of the control magnet valve devices will occur, the retardation controlle-r I1 thus maintaining the degree of application of the brakes within the desired limits.

If during the operation of the vehicle the winding |9| of the emergency relay I9 becomes deenergized for any reason, such as by release of manual pressure on the deadman switch 2i, the operation of the conductors switch 22, or upon interruption in any other manner of the train line circuit comprising these two switches, the emergency relay contact members |92 and |93 will drop to their lower positions. As the contact member |52 drops to its lower position the circuit through` the magnet winding of the local supply magnet valve devices i5 is interrupted and the valve |45 is forced to its seat by the spring |48. As the contact member |93 drops to its lower position a circuit is completed from the positive terminal of the battery 29@ through conductor |95, contact member |93, to conductor 298. From the conductor 25S the circuits are completed as above traced through the magnet windings of the supply magnet valve device I3 and of the discharge magnet valve device |5 to the negative terminal of the battery 299, thus moving the valve 12 to its seat to prevent the supply of fluid under pressure from the main reservoir I| to the brake pipe 9, and moving tre valve |31 from its seat for effecting the release of fluid under pressure from the brake pipe 9 through the discharge magnet valve device I5, to effect an application of the brakes independently of the operation of the brake valve device I4.

While I have illustrated and described one preferred embodiment of my invention it will be apparent to those skilled in the art that many changes in the illustrated apparatus may be made within the spirit of my invention, and I do not wish to be limited otherwise than by the scope oi the appended claims.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is:

l. In a brake equipment for vehicles, a brake cylinder, means for supplying fluid under pressure to said brake cylinder, a brake pipe, a selflapping brake valve device for reducing brake pipe pressure any desired amount below a predetermined value in accordance with the amount of movement from its release position to eiect a desired degree of application of the brakes, a relay valve device responsive to brake pipe pressure for controlling the supply of fluid under pressure to said brake cylinder', said relay valve device comprising a piston chamber and valve means operative in accordance with the pressure in said piston chamber for controlling the supply of fluid under pressure to said brake cylinder, means comprising a lever arm and valve mechanism actuated thereby for controlling the pressure in said piston chamber, and means responsive to a decrease in brake pipe pressure below a predetermined value for actuating said lever arm to effect the supply of fluid under pressure to said piston chamber in accordance with the reduction in brake pipe pressure below said predetermined value.

2. In a brake equipment for vehicles, a brake cylinder, means for supplying fluid under pressure to said brake cylinder, a brake pipe, and means for reducing brake pipe pressure any desired amount below a predetermined value to effect a desired degree of application of the brakes,` a relay valve device responsive to brake pipe pressure for controlling the supply of fluid under pressure to said brake cylinder, said relay valve device comprising a piston chamber and valve means for controlling the supply of fluid under pressure to said brake cylinder for effecting a brake cylinder pressure corresponding to the pressure in said piston chamber, valve means for controlling the supply of fluid under pressure to said piston chamber and valve means for elicoting communication between said piston chamber and the atmosphere, valve operating mechanism comprising a rotatable member and biasing means for operating said member in a direction to effect movement of said rst named valve means to open communication therethrough and for operating said second named valve means to close communication therethrough, and pressure means responsive to brake pipe pressure for opposing said biasing means to close communication through said rst named valve means and to open communication through said second named valve means.

3. In a brake equipment for vehicles, a brake cylinder, means for supplying fluid'under pressure to said brake cylinder, a brake pipe, and means for reducing brake pipe pressure any desired amount below a predetermined value to effect a desired degree of application of the brakes, a reiay valve device responsive to brake pipe pressure for controlling the supply of fluid under pressure to said brake cylinder, said relay valve device having a piston chamber and valve means for controlling the supply of fluid under pressure to said brake cylinder for effecting a brake cylinder pressure corresponding to the pressure in said piston chamber, valve operating mechanism comprising a rotatively mounted shaft, valve means operatively connected to said shaft for controlling the supply of fluid under pressure to said piston chamber', valve means operatively connected to said shaft for effecting communication between said piston chamber and the atmosphere, biasing means for urging said shaft to a position to cause said first named Valve means to open communication therethrough and to cause said second named valve means to close communication therethrough, and pressure responsive means responsive to brake pipe pressure for opposing said biasing means to close communication through said first named valve means and to open communication through said second named valve means, and means responsive to the pressure in said piston chamber for opposing said biasing means to effect the operation of said valve means to maintain the pressure in said piston chamber at a value corresponding to the reduction in brake pipe pressure below said predetermined value.

4. In a brake equipment for vehicles, a brake cylinder, a brake pipe, a manually operable selflapping brake valve device having a supply valve and a discharge valve therein for controlling the reduction in the brake pipe pressure below a predetremined value in accordance with the degree of movement of the brake valve handle from its release position, a relay valve device responsive to brake pipe pressure for controlling the supply of fluid under pressure to said brake cylinder to effect and maintain a brake cylinder pressure corresponding to said reduction in brake pipe pressure below said predetermined value, said relay valve device having a piston chamber and valve means operated in accordance with the pressure in said piston chamber, for effecting the supply of fluid under pressure to said brake cylinder, means for effecting communication between said piston chamber and the atmosphere when brake pipe pressure is above a predetermined value, means subject to a decrease in brake pipe pressure below said predetermined value for supplying fluid under pressure to said piston charnber in accordance with the reduction in brake pipe pressure below said predetermined value a supply magnet valve device and a discharge magnet valve device for also controlling brake pipe pressure, and means for effecting operation of said supply and discharge magnet valve devices in accordance with the operation of the supply and discharge valves, respectively,y of said brake valve device.

5. In a brake equipment for vehicles, a brake cylinder, a brake pipe, a manually operable selflapping brake valve device having a supply valve and a discharge valve for controlling the supply of fluid under pressure to, and the release of iiuid under pressure from, said brake pipe in accordance with the amount of movement of the brake valve handle, a relay valve device responsive to brake pipe pressure for controlling the supply of fluid under pressure to said brake cylinder to effect and maintain a brake cylinder pressure corresponding to the reduction in'brake pipe pressure below a predetermined value, a supply magnet valve device and a discharge magnet valve device for controlling the supply of uid under pressure to, and the release of fluid under pressure from, said brake pipe, means controlled by said brake valve device for effecting operation of said magnet valve devices simultaneously with the operation of the corresponding valves of said brake valve device, and a retardation controller responsive to the rate of retardation of said vehicle for controlling brake pipe pressure to effect a desired rate of retardation of the vehicle. 6. In a brake equipment for vehicles, a brake cylinder, a brake pipe, a manually operable selflapping brake valve device having a supply valve and a discharge valve for controlling the supply of fluid under pressure to, and the discharge of fluid under pressure from, said brake pipe in accordance with the amount of movement of the brake valve handle, a relay valve device responsive to brake pipe pressure for controlling the supply of fluid under pressure to the brake cylinder to effect and maintain a brake cylinder pressure corresponding to the reduction in brake pipe pressure below a predetermined value, a supply magnet valve device and a discharge magnet valve device for controlling the supply of iiuid under pressure to, and the release of fluid under pressure from, said brake pipe, and switch contact means associated with the supply valve and the discharge valve of said brake valve device for controlling the magnet valve devices to effect the supply of fluid under pressure to, and the release of uid under pressure from, said brake pipe through said magnet valve devices corresponding to like operations of said brake valve device. 7. In a brake equipment for Vehicles, a brake cylinder, a brake pipe, a manually operable selflapping brake valve device having a supply valve and a release valve for controlling the supply of fluid under pressure to, and the release of fluid under pressure from, said brake pipe in accordance with the movement of the brake valve handle, a relay valve device responsive to brake pipe pressure for controlling the supply of fluid under pressure to said brake cylinders to effect and maintain a brake cylinder pressure corresponding to the reduction in brake pipe pressure below a predetermined value, a supply magnet valve device and a discharge magnet valve device for controlling the supply of uid under pressure to, and the release of fluid under pressure from,

. said brake pipe, and switch contact means associated with the supply valves andthe release valves of said brake valve device for controlling the magnet valve devices to effect the supply of fluid under pressure to, and the release of uid under pressure from, said brake pipe, through said magnet valve devices corresponding to like operations of said brake valve device, and a retardation controller responsive to the rate of retardation of the vehicle for controlling the operation of said magnet valve devices to so control brake pipe pressure as to effect a desired rate of retardation of the vehicle.

8. In a brake equipment for vehicles, in combination, a brake cylinder, a brake pipe, means responsive to a reduction in brake pipe pressure for supplying`V fluid under pressure to said brake cylinder, a brake valve device having supply and release valves for controlling said brake pipe pressure, supply magnet valve devices spaced along said brake pipe for also controlling the supply of fluid under pressure to said brake pipe, release magnet valve devices spaced along said brake pipe for also controlling the release of iuid under pressure from said brake pipe, and electrically operated means for controlling said supply and release magnet valve devices including switches controlled, respectively, by the supp-ly valve and the release valve of said brake valve device to effect the simultaneous supply of fluid under pressure to, or the simultaneous release of yfluid under pressure from, said brake pipe at a number of different points.

9. In a brake equipment for vehicles, in cornbination, a brake pipe, a brake valve device for controlling the supply of uid under pressure to, and the release of fluid under pressure from, said brake pipe, a plurality of braking units comprising a brake cylinder, means responsive to brake pipe pressure for controlling the supply of fluid under pressure to, and the release of fluid under pressure from, said brake cylinder, to control brake cylinder pressure inversely with variations in brake pipe pressure below a predetermined value, magnet valve devices associated with each braking unit for also controlling the supply of fluid under pressure to, and the release of fluid under pressure from, said brake pipe, a train wire extending through the train, means for interrupting the circuit through said train wire,

rand means normally energized through said train wire and responsive to the interruption of said train wire circuit for controlling the operation of said magnet valve devices independently of the position of said brake valve device to effect a full service application of the brakes.

10. In a brake equipment for vehicles, in combination, a brake pipe, a brake valve device for 'controlling the supply of fluid under pressure to,

and the release of iluid under pressure from, said -brake pipe, a plurality of braking units each comprising a brake cylinder, means responsive to brake pipe pressure for controlling the supply of fluid under pressure to said brake cylinder,

,magnet valve devices associated with each brakving unit for also controlling the supply of uid under pressure to, and the release of fluid under pressure from, said brake pipe, a train wire extending through the train, means for interrupting the circuit through said train wire, Aand means normally energized through said train wire and operative upon the interruption of said train Wire circuit for controlling the operation of said magnet valve devices independently of the DOSition of said brake valve device to effect a full service application of the brakes.

11. In a brake equipment for vehicles, in combination, a brake cylinder, a brake pipe, means responsive to a reduction in brake pipe pressure for supplying fluid under pressure to said brake cylinder, a brake valve device having supply and release valves for controlling brake pipe pressure, supply magnet valve devices spaced along said brake pipe for also controlling the supply of uid under pressure to said brake pipe, release magnet valve devices for also controlling the release of fluid under pressure from said brake pipe, electrical means comprising control circuits for said magnet valve devices and switches controlled respectively by the supply valve and the release valve of said brake valve device for operating and magnet valve devices to effect the simultaneous supply of fluid under pressure to,

Aand the simultaneous release of uid under pressure from, said brake pipe at a number of different points, a train wire extending through the train means for interrupting the circuit through said train wire and means normally energized through said train Wire and operative upon the interruption of said train wire circuit for controlling the operation of said magnet valve devices independently of said brake valve device to eiect a full service application of the brakes.

l2. In a brake equipment for vehicles, in combination, a brake cylinder, a brake pipe, means responsive to a reduction in brake pipe pressure for supplying fluid under pressure to said brake cylinder, a brake valve device having supply and release valves for controlling said brake pipe pressure, magnet valve devices associated with each braking unit and controlled by said brake valve device for effecting the simultaneous supply or release of fiuid under pressure to and from said brake pipe to control the application and release of the brakes, a train wire extending through the train, means for interrupting the circuit through said train wire, and means normally energized through said train wire and operative upon the interruption of said train wire circuit for controlling the operation of said magnet valve devices, independently of the position of said brake valve device, to effect a full service application of the brakes.

13. In a brake equipment for vehicles, in combination, a brake cylinder, a brake pipe, means responsive to a reduction in brake pipe pressure for supplying fluid under pressure to said brake cylinder, a brake valve device having supply and release valves for controlling brake pipe pressure, magnet valve devices associated with each braking unit and controlled by said brake valve device for effecting the simultaneous supply or release of uid under pressure from said brake pipe, a supply magnet valve device for controlling the flow of fluid under pressure from a source of supply to said brake valve device, a train wire extending through the train, means for interrupting the circuit through said train wire, means normally energized through said train wire and operated upon the interruption of said train wire 'circuit for controlling the operation of said several magnet valve devices independently of the position of said brake valve device to effect a full service application of the brakes, and of said supply magnet valve device to cut off the supply of uid under pressure to said brake valve device.

14. In a brake equipment for vehicles, in combination, a brake cylinder, a brake pipe, means responsive tol a reduction in brake pipe pressure for supplying fluid under pressure to said brake cylinder, a brake valve device having supply and release valves for controlling said brake pipe pressure, supply magnet valve devices associated with a 'plurality of braking units spaced along said brake pipe for also controlling the supply of fluid under pressure to said brake pipe, discharge magnet valve devices -associated with said several braking units spaced along said brake pipes for also controlling the release of uid under pressure from said brake pipe, -electric means including switches controlled, respectively, by the supply valve and the release valve of said brake valve device'for controlling the operation of said magnet valve devices to VIeffect the simultaneous supply of uid under pressure to, or the simultaneous release of fluid under pressure from, saidbrake pipe at a number of different points, a supply magnet Valve device for controlling the flow of fluidA under pressure from a main reservoir to said brake device, a train wire extending through the train, means for interrupting the circuit through the said train Wire, means normally energized through said train Wire and operated upon the interruption of said train Wire circuit for controlling the operation of said braking unit magnet valve devices independently of the position of said brake valve device to effect a full service "application of the brakes, and to effect operation of said supply magnet valve device to cut olf the supply of fluid under pressure to said brake valve device.

15. In a brake equipment for vehicles, in combination, a brake pipe,v a brake valve device for controlling the supply of fluid under pressure to, and the release of fluid under pressure from, said Vbrake pipe, a plurality of braking units each comprising a brake cylinder and means responsive to brake pipe pressure for controlling the supply of fluid under pressure to said brake cylinder, magnet valve devices associated with each braking unit for also controlling the supply of fluid under pressure to, and the release of fluid under pressure from, said brake pipe, a supply magnet valve device for controlling the ilovv of uid under pressure from a main reservoir to said brake valve device, a train Wire extending through the train, means for interrupting the circuit through said train Wire, and means normally energized through `said train wire and operated upon interruption of said train` wire circuit for controlling the operation of said magnet valve devices independently of the position of said brake valve device to effect a full service application of the brakes and to effect operation of said supply magnet valve device to cut off the supply of fluid under pressure to said brake valve device.

16. In a brake equipment for vehicles, in combination, a brake cylinder, a brake pipe, means responsive to a reduction in brake pipe pressure for controlling the supply of uid under pressure to said brake cylinder, a brake valve device having supply and release valves for controlling the said brake pipe pressure, magnet valve devices associated With each braking unit and controlled by said brake valve for effecting the simultaneous supply or release of fluid under pressure from said brake pipe at the brake valve device and at each braking unit, a discharge cut-olf magnet valve device for limiting the release of uid under pressure from said brake pipe through said brake valve device, a retardation controller device responsive to the rate of retardation of the vehicle, circuits controlled by said retardation controller .device'for governing the brake controlling magnet valve devices for effecting an increase in brake pipe pressure when the rate of retardation of the vehicle exceeds the desired amount and for controlling the discharge cut-off magnet valve device to prevent the further release of fluid under pressure from said brake pipe through said brake valve device.

1'7. In a brake equipment for vehicles, in combination, a brake cylinder, a brake pipe, means responsive to a reduction in brake pipe pressure for supplying fluid under pressure to said brake cylinder, a brake valve device having supply and discharge valves for controlling said brake pipe pressure, supply magnet valve devices for also controlling the supply of fluid under pressure to said brake pipe, release magnet valve devices for also controlling the release of fluid under pressure from said brake pipe, electrical means comprising switches controlled by said supply valve and said release valve, respectively, of said brake valve device for controlling the simultaneous operation of said several valves to effect the supply of iiuid under pressure to, or the release of fluid under pressure from, said brake pipe, a discharge cut-ofi magnet valve device for limiting the discharge of fluid under pressure from said brake pipe throughsaid brake valve device, a retardation controller responsive to the rate of retardation of the vehicle, and circuits controlled by said retardation controller for governing the brake controlling magnet valve devices for effecting an increase in brake pipe pressure and for controlling the discharge cut-off magnet valve device to prevent the further release of fluid under pressure from` said brake pipe through said magnet valve device.

18. In a brake equipment for vehicles, in combination, a brake pipe, a brake Valve device for controlling the supply of fluid under pressure to, and the release of fluid under pressure from, said brake pipe, a plurality of braking units each comprising a brake cylinder and means responsive to brake'pipe pressure for controlling the supply of fluid under pressure to said brake cylinder, magnet valve devices associated with each braking unit for also controlling' the supply of fluid under pressure to, and the release of iiuid under pressure from, said brake pipe, a discharge cutoff magnet valve device for limiting the discharge of uid under pressure from said brake pipe through said brake valve device, a retardation controller device responsive tothe rate of retardation of the vehicle, and circuits controlled by said retardation controller device for governing the brake controlling magnet valve devices for effecting an increase in brake pipe pressure and for controlling the discharge cut-off magnet valve device to prevent the further release of fluid under pressure from said brake pipe through said brake valve device.

19. In a brake equipment for vehicles, in combination, a brake pipe, a brake valve device for controlling the supply of fluid under pressure to said brake pipe and for eiecting a reduction in brake pipe pressure an amount corresponding to a degree of movement of said brake valve device from its release position, a plurality of braking units each comprising a brake cylinder and a relay valve device for controlling thesupply of fluid under pressure to, and the release of uid ,under pressure from, the brake cylinder, said relay valve device comprising valve mechanism for controlling brake cylinder pressure, a fulcrumed valve operating mechanism, biasing means effective to operate' said relay valve device to full service-application position, and two pressure operated devices for opposing said biasing means having pressure responsive elements of equal area, one of said pressure operated devices being responsive to brake pipe pressure, and the other being responsive to brake cylinder pressure.

20. In a brake equipment for vehicles, in combination, a brake pipe, a brake valve device for controlling the supply of uid under pressure to said brake pipe and for effecting a desired reduction in brake pipe pressure, a plurality of braking units each comprising a brake cylinder and means including a relay valve device for controlling the supply of fluid under pressure to, and the release of fluid under pressure from, said brake cylinder, said relay valve device comprising valve mechanism for controlling brake cylinder pressure, a fulcrumed valve operating mechanism, biasing means effective to urge said valve operating mechanism to service application position, and two pressure operated devices for opposing said biasing means having pressure responsive elements of equal area and having equal radii of application about said fulcrum to cause said mechanism to be responsive to a reduction in the sum of the values of brake pipe pressure and brake cylinder pressure below a predetermined value for effecting the supply of fluid under pressure to said brake cylinder, and responsive to an increase in the sum of the value of brake pipe pressure and brake cylinder pressure above said predetermined value for effecting the release of uid under pressure from said brake cylinder.

21. In a brake equipment for vehicles, in combination, a brake pipe, means for reducing brake pipe pressure any desired amount below a predetermined value, a brake cylinder, a relay valve device having valve means for controlling the supply of fluid under pressure to and the release of fluid under pressure from said brake cylinder and control means for said valve means comprising a fulcrumed lever, biasing means for biasing said lever to a position to effect the supply of fluid under pressure to said brake cylinder, and a pair of pressure responsive means for actuating said lever against the opposition of said biasing means, one of said pressure responsive means being responsive to brake cylinder pressure and the other being responsive to brake pipe pressure.

22. In a vehicle brake system, in combination, fluid pressure brake means, a brake pipe, means operated upon a reduction in brake pipe pressure for effecting an application of said brake means and operative upon an increase in brake pipe pressure for effecting a release of said brake means, and means operative at a chosen rate of retardation of the vehicle to increase brake pipe pressure to effect a release of said brake means.

23. In a vehicle brake system, in combination, fluid pressure brake means, a brake pipe, means operated upon a reduction in brake pipe pressure for effecting an application of said brake means and operative upon an increase in brake pipe pressure for effecting a release of said brake means, a retardation controller device operated according to the rate of retardation of the vehicle, and electroresponsive means responsive to operation of said retardation controller device at a chosen rate of retardation to increase brake pipe pressure to effect a release of said brake means.

24. In a vehicle brake system, in combination, fluid pressure brake means, a brake pipe, means operated upon a reduction in brake pipe pressure for effecting an application of said brake means, electroresponsive means for effecting an increase in brake pipe pressure to effect a release of said brake means, a brake valve device for manually controlling operation of said electroresponsive means, and a retardation controller device operated according to the rate of retardation of the vehicle for also controlling said electroresponsive means.

JOHN W. LOGAN, JR.

Patent No 2,8L\., 695 u CERTiFicATE or CORRECTION.

` June 22, 1957.

JOHN w. LoGAN, JR.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correetion as follows: kPage 8, second column, line 5, after the word "value" insert a comme; Page 9, second column, line 18, claim ll, for "and read, said; line 25, seme claim, after "trin" insert a comma; and that the said Letters Patent should be read with' these corrections therein that the same may conform to the record of the case' in the 'Patent Cffoe. I v

signed and sealed this 12th day ofoctober, A. D. 1957.

. Henry Van Arsdale. (Seal) Acting Commissioner of Patents. 

